Ctjbbeits



P C. HEWITT.-

' METHOD OF AND MEANS FOR VARYING THE FREQUENCY OF AN OSCILLATING CURRENT.

APPLICATION FILED MAYIZ. 1914.

1,321,436. v Patented Nov. 11,1919. I

WITNESSES 13mm Em inane san rss carrier or PETER- COOIPER HEWITT, OF BINGWOOD MANOR, NEW JERSEY.

METHOD 03' AND MEANS FOR VARYING THE FREQUENCY OF AN OSCILLATING CURRENT.

Specification of Letters raten't,

Patented n ev. aft, 3919.

Application filed May 12, 1914. Serial No. 838,038.

To aZZ "whom 2'5 may concern:

Be it known that 1, PETER COOPER Hiaw- 1T1, a citizen of the United States, residing at Ringwood Manor, in the county of Passaic and State of New Jersey, have invented certain new and useful Improvements in Methods of and Means for arying the l' requency or an Oscillating lurrent, of which the followin is a specification.

My present invention relates to method of and means for varying the frequency of a periodic or alternating current produced in a circuit including a gas or vapor tube in connection with a condenser.

I have discovered that the frequency of the currents produced by such apparatus may be varied by impressing a variable electric or magnetic field on the space between the electrodes of the gas or vapor tube. As the intensity of the field increases, the frequency of the periodic or alternating currents decreases a d as the intensity of the eld decreases the trequency of periodic or alternating currents increases. Such changes in frequency may be usefully mployed in various arts, among them the arts of wireless telegraphy or telephony and mo tor control.

In patents already issued to mefor in stance, No. 682.695, No. 682,696 and No. 682,697. all dated September 17 i901, and in pending applications Serial Nos. 838.033. 838.033, 838034, 838.035, 838,037, filed May 12th, 1914, I have fully described the construction and operation of mercury vapor tubes of the general type illustrated in ill'w drawings of this application. and therefor need not repeat the description of the general principles in this application. While I have shown herein only a mercury vapor tube, it will be understood that any other analogous gas or vapor or evacuated tube' may be employed.

Tn the accompanying drawings 1 is a mercury tube in which 2 is the main positive ele trode and 3 the negative electrode. 10 is an auxiliary or keep alive positive electrode. and 1-2 the independent circuit supplying current to the same. The tube has a reiintrant portion 4% forming an annular space 5 for the current. 13 is an electromagnet the field of which is impressed on the space between the main electrodes, The means for producing the magnetic field may consist of a plurality of windings surrounding the tube and also an additional winding located within the reentraut portion of the tube. 17 is acondenser and 18 is an inductance. W indicates the work circuit, in this case containing incandescent lamps. 18, 18, are inductances on the line.

The magnet 13 is energized by any suitable source of current, indicated at 20, and

this circuit includes means for varying thecurrent, which is indicated diagrammatically at 19. 'As the current is varied, the field of the i'nagnet 13 is varied, and, as already explained, the frequency of the periodic 'or alternating currents, or the rate of oscillation, is varied.

'ihe term gas or vapor tube as used in these specifications and in the claims is intended to include all forms of devices which are the equivalent of a mercury tube for the purposes of this invention, irrespective of the contents of the tube or container, and irrespective oi the means employed to keep the negative electrode alive, or to keep the resistance to starting at the negative electrode at a low value. The term, therefore, as used may include, for example, a tube exhausted to any degree, or a suitable current fiow in air or other gas, and may include a device in which the negative electrode is kept constantly alive, or in which the resistance to starting at the negative electrode is maintained at a low value, by being highly heated and may include any path between electrodes controlled mechanically or electrically, Where the resistance to starting at the negative electrode is maintained at a low value.

\Vhat I claim and desire to secure by Letters Patent of the United States is:

l. The method of controlling the frequency of periodic Currents traversing a. confined vaeu um, gas, or vapor path, which consists in subjecting the path to magnetic lines of force and increasing the lines of torcefor decreasing the frequency and decreasing the lines of force for increas g the frequency, and in regulating the ncrease and decrease of the field.

2. The method of controlling the frequency of periodic currents traversing a confined vacuum, gas, or vapor path, which consists in subjecting the path to magnetic lines of force and increasing the lines of force for decreasing the frequency, and in regulating the increase and decrease of the field.

The method of controlling the frequenry of periodic currents traversing a conllltill'lr'? for impressing a magnetic field on the ql vacuunr gas or va mr )ath. which con- HULl annular s iare to raw the fret. uencv of 1 \4 7 l I I I.

oi force and decreasing the lines of force and means for rar ving the intensity of said for inlizreasing the frequency, and in regufield. lating the inrreaseand decrease of the field. (i. The combination with a Vacuum, gas,

t. The combination with a condenser, of or vapor device, of means including a cona or rapor tube having an annular condenser for causing periodic or inherently 30 ducting space extending between the eleefarting rurrents to flow therethrough, means trodes of said tube and parallel to the difor establishing a field of foree,the lines of rectum of current flow between said elecr-thioh traverse said path, and means for trodes, means for impressing a magnetic regulating the i1'1lCHSllL of such field at Will field on the said annular space to vary the for modifying: the frequency of the current 35 frequency of the condenser discharge through \ariations. said tube, and means for varying the in In testimony whereo'l l have hereui'ito tensity of said field. si ued my name in the presiaiee of two sub- The combination with a condenser, of scribing Witnesses. a as or raver tube havin an annular con n 'w i 1 l 1 1 1 diiizling Spill-f0 parallel te t-he direction of l 'ZFEL O ER HIWVIF'IT' current flow between the electrodes of said llitnesses: tube, the resistance of one of said electrodes L. A. Cowman, being maintained below its natural value, H. A. l'ilill'l'm.

Copies of this patent may be obtained for five cents each by addressing the Commissioner of Patents,

Washington, .6. i

a in subjettingthe path to magnetic lines the condenser discharge through said tube, 25 

